1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- W I D E C H A R -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2018, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- Subprograms for manipulation of wide character sequences. Note that in 33-- this package, wide character and wide wide character are not distinguished 34-- since this package is basically concerned with syntactic notions, and it 35-- deals with Char_Code values, rather than values of actual Ada types. 36 37with Types; use Types; 38 39package Widechar is 40 41 Wide_Char_Byte_Count : Nat := 0; 42 -- This value is incremented whenever Scan_Wide or Skip_Wide is called. 43 -- The amount added is the length of the wide character sequence minus 44 -- one. This means that the count that accumulates here represents the 45 -- difference between the length in characters and the length in bytes. 46 -- This is used for checking the line length in characters. 47 48 function Length_Wide return Nat; 49 -- Returns the maximum length in characters for the escape sequence that 50 -- is used to encode wide character literals outside the ASCII range. Used 51 -- only in the implementation of the attribute Width for Wide_Character 52 -- and Wide_Wide_Character. 53 54 procedure Scan_Wide 55 (S : Source_Buffer_Ptr; 56 P : in out Source_Ptr; 57 C : out Char_Code; 58 Err : out Boolean); 59 -- On entry S (P) points to the first character in the source text for 60 -- a wide character (i.e. to an ESC character, a left bracket, or an 61 -- upper half character, depending on the representation method). A 62 -- single wide character is scanned. If no error is found, the value 63 -- stored in C is the code for this wide character, P is updated past 64 -- the sequence and Err is set to False. If an error is found, then 65 -- P points to the improper character, C is undefined, and Err is 66 -- set to True. 67 68 procedure Set_Wide 69 (C : Char_Code; 70 S : in out String; 71 P : in out Natural); 72 -- The escape sequence (including any leading ESC character) for the 73 -- given character code is stored starting at S (P + 1), and on return 74 -- P points to the last stored character (i.e. P is the count of stored 75 -- characters on entry and exit, and the escape sequence is appended to 76 -- the end of the stored string). The character code C represents a code 77 -- originally constructed by Scan_Wide, so it is known to be in a range 78 -- that is appropriate for the encoding method in use. 79 80 procedure Skip_Wide (S : String; P : in out Natural); 81 -- On entry, S (P) points to an ESC character for a wide character escape 82 -- sequence or to an upper half character if the encoding method uses the 83 -- upper bit, or to a left bracket if the brackets encoding method is in 84 -- use. On exit, P is bumped past the wide character sequence. No error 85 -- checking is done, since this is only used on escape sequences generated 86 -- by Set_Wide, which are known to be correct. 87 88 procedure Skip_Wide (S : Source_Buffer_Ptr; P : in out Source_Ptr); 89 -- Similar to the above procedure, but operates on a source buffer 90 -- instead of a string, with P being a Source_Ptr referencing the 91 -- contents of the source buffer. 92 93 function Is_Start_Of_Wide_Char 94 (S : Source_Buffer_Ptr; 95 P : Source_Ptr) return Boolean; 96 -- Determines if S (P) is the start of a wide character sequence 97 98private 99 pragma Inline (Is_Start_Of_Wide_Char); 100 101end Widechar; 102